Conventionally, in coloration of a polyolefin, such as polyethylene and polypropylene, an inorganic pigment, such as an oxide, a sulfide and a sulfate of various metals, and an organic pigment, such as a phthalocyanine-type one, a quinacridone-type one and a benzidine-type one have been used usually.
However, the inorganic pigment has a problem of lacking in colorability, dispersibility and vividness, although it is excellent in heat resistance, weatherability, solvent resistance and chemical resistance. In addition, the organic pigment has a problem of color change due to decomposition or receiving change of a crystal structure caused by heat, in coloring the polyolefin requiring a high molding temperature. Because of these problems, among resin processing manufacturers, there has been extraordinary difficulty in the selection of the pigment to be used for coloring the polyolefin.
On the other hand, an organic dye has been used little, because of color migration or fading caused by bleed-out after coloring, although it shows vivid color development and transparency as compared with a pigment.
Big reason thereof is that, in the case of the dye, kneading of the dye and the polyolefin becomes insufficient, because a structure of the polyolefin itself is a chain-like structure composed of carbon and hydrogen, as well as the polyolefin has a relatively hydrophobic surface layer; and therefore, there is a problem of insufficient dispersion of the dye in the polyolefin, and no immobilization.
As a method for integrating other organic substances with the polyolefin, techniques for subjecting other reactive organic substances to a graft reaction are known, for example, as shown by the following (1) to (3):    (1) A method for producing a modified polyolefin by compounding a radical polymerizable monomer, such as acrylic acid, methacrylic acid and maleic anhydride, and a radical polymerization initiator, to a polyolefin, and then carrying out a graft reaction under melting (refer to PATENT LITERATURE 1);    (2) A method for continuously producing a modified polyolefin by the addition of a vinyl monomer, such as styrene, acrylonitrile and (meth)acrylic acid to a polyolefin, and then carrying out a graft polymerization, in the presence of a radical polymerization initiator, by using a bulk polymerization method, a bulk-suspension polymerization method, or a solution polymerization method (refer to PATENT LITERATURE 2);    (3) A method for producing a modified polyethylene by a graft polymerization of N,N-diethylacrylamide to a polyethylene, in the presence of a radical initiator, in a molten state of polyethylene (refer to PATENT LITERATURE 3).
However, these techniques are not the methods for producing the colored substance integrating the polyolefin and the dye, because in any of them the reactive organic substances are other monomers, and not a coloring compound such as the dye.
In addition, a technique for producing a colored polymer has also been known, which a monomer mixture containing a specific reactive dye represented by the next formula (1), mixed in alkyl (meth)acrylates, a hydrophilic monomer, or the like, is copolymerized in the presence of a cross-linking agent (refer to PATENT LITERATURE 4).

However, this technique is the one applicable to a monomer stage, as well as a target resin is the one other than the polyolefin, which limit applications thereof, and therefore, it was the one never utilizable as a master batch for coloring other resins.
On the other hand, as a method for integrating the dye into the polyolefin, there has been known, for example, a polypropylene colored composition for producing a vivid color article containing nylon, a compatibilizing agent and a dye in polypropylene (refer to PATENT LITERATURE 5), or a colored polyolefin-type resin composition containing a sorbitol-type compound and a metal-containing dye in a polyolefin-type resin (refer to PATENT LITERATURE 6).
However, these techniques are not the ones where the polyolefin and the dye are organically bonded, and thus cannot be said that the dye is sufficiently adhered to the polyolefin, and had a problem in view of fastness, of possibility of bleed-out, or the like.
Under such circumstances, research and development has been desired, in coloring the polyolefin, for the colored resin that is free from color migration or fading caused by bleed-out after coloring, which is the defect of the dye, without impairing vivid color development and transparency of the dye.